Your goal in the first day is to stop self-trauma, gently clean the surface, and keep the area dry so it can calm down instead of spreading.
1) Prevent licking immediately: Use an e-collar (cone) or a well-fitted recovery collar. If licking continues, the lesion usually enlarges.
2) Expose the area to air without aggressive at-home shaving: Part the coat and remove loose, damp fur around the patch with your fingers or a comb if it doesn’t pull. Avoid cutting close to the skin—uneven clipping can nick inflamed tissue and worsen irritation.
3) Gentle cleansing: Rinse with lukewarm water or use a mild, vet-approved antiseptic wash if you already have one. Pat dry thoroughly. Do not use hydrogen peroxide, as it can damage healing tissue.
4) Keep it dry: Avoid occlusive ointments that trap moisture unless your veterinarian specifically directs you to use them.
Vet-now triggers: a large or rapidly expanding area, foul odor, pus or thick discharge, severe pain, marked swelling, lesions on the face/genitals, or any signs of systemic illness (lethargy, fever, not eating).